Wakefield G H, Viemeister N F
Department of Psychology, University of Minnesota, Minneapolis 55455.
J Acoust Soc Am. 1990 Sep;88(3):1367-73. doi: 10.1121/1.399714.
The detection of sinusoidal amplitude modulation (SAM) provides a lower bound on the degree to which temporal information in the envelope of complex waveforms is encoded by the auditory system. The extent to which changes in the amount of modulation are discriminable provides additional information on the ability of the auditory system to utilize envelope fluctuations. Results from an experiment on the discrimination of modulation depth of broadband noise are presented. Discrimination thresholds, expressed as differences in modulation power, increase monotonically with the modulation depth of the standard, but do not obey Weber's law. The effects of carrier level and of modulation frequency are consistent with those observed in modulation detection: Changes in carrier level have little effect on modulation discrimination; changes in modulation frequency also have little effect except for standards near the modulation detection threshold. The discrimination of modulation depth is consistent with the leaky-integrator model of modulation detection for standards below--10 dB (20 log ms); for standards greater than--10 dB, the leaky integrator predicts better performance than that observed behaviorally.
正弦幅度调制（SAM）的检测为听觉系统对复杂波形包络中的时间信息进行编码的程度提供了一个下限。调制量变化的可辨别程度为听觉系统利用包络波动的能力提供了额外信息。本文展示了一项关于宽带噪声调制深度辨别的实验结果。以调制功率差异表示的辨别阈值随标准的调制深度单调增加，但不遵循韦伯定律。载波电平及调制频率的影响与调制检测中观察到的一致：载波电平的变化对调制辨别影响很小；调制频率的变化除了标准接近调制检测阈值时也影响很小。对于低于 -10 dB（20 log ms）的标准，调制深度的辨别与调制检测的泄漏积分器模型一致；对于大于 -10 dB的标准，泄漏积分器预测的性能优于行为观察到的性能。
